1. Field of the Invention
The present invention relates to a mold for molding a plastic resin or the like, the mold having a fine structure composed of at least one of a cavity and a core on the micrometer order, or preferably the nanometer order, a method of producing the mold, and a method of producing a molded article using the mold.
2. Description of the Related Art
With recent development of nanotechnologies, molded articles having a fine structure have been used in various fields. For example, molded articles having a fine structure, such as a semiconductor circuit, a DNA chip substrate, a nozzle of an ink-jet head, and a sensor have been used. These molded articles require high dimensional accuracy. For example, a smaller nozzle diameter of an ink-jet head allows a large amount of information to be processed. Molded articles constituting a micromachine component also require a fine structure having a high dimensional accuracy.
Hitherto, in the field of die, dies are processed by electric discharge machining, and dies having a fine structure with a size on the order of 5 to 10 μm have been produced. However, for example, in order to produce molded articles constituting components of micromachines, a mold such as a die that is subjected to an ultra-micromachining on the order of 1 μm or less is required. A processing method using ion beam irradiation has been tried as processing means for performing, on a mold material, a micromachining of such a fine size, which exceeds the limit of the processing accuracy of the electric discharge machining (see, for example, Japanese Unexamined Patent Application Publication No. 2004-034194).
In the processing method using ion beam irradiation, a throughput (process efficiency) is significantly changed in accordance with combinations of a metallic material to be processed and an ion atom. In addition, the irradiated ion must have energy sufficient to satisfactorily knock off atoms of the metal to be processed by collision. Furthermore, for example, when a mold is produced by processing copper (Cu) by Ga ion irradiation, it takes a very long time and effort. For example, when a cubic cavity having ten micrometer sides is formed on a copper (Cu) material with a focused ion irradiation device in which Ga ions are accelerated at 30 kV, a processing time in the range of several hours to ten hours is required.